Demographic Transition - Stage Two

Stage Two

This stage leads to a fall in death rates and an increase in population. The changes leading to this stage in Europe were initiated in the Agricultural Revolution of the 18th century and were initially quite slow. In the 20th century, the falls in death rates in developing countries tended to be substantially faster. Countries in this stage include Yemen, Afghanistan, the Palestinian territories, Bhutan and Laos and much of Sub-Saharan Africa (but do not include South Africa, Zimbabwe, Botswana, Swaziland, Lesotho, Namibia, Kenya and Ghana, which have begun to move into stage 3).

The decline in the death rate is due initially to two factors:

• First, improvements in the food supply brought about by higher yields in agricultural practices and better transportation prevent death due to starvation and lack of water. Agricultural improvements included crop rotation, selective breeding, and seed drill technology.
• Second, significant improvements in public health reduce mortality, particularly in childhood. These are not so much medical breakthroughs (Europe passed through stage two before the advances of the mid-20th century, although there was significant medical progress in the 19th century, such as the development of vaccination) as they are improvements in water supply, sewerage, food handling, and general personal hygiene following from growing scientific knowledge of the causes of disease and the improved education and social status of mothers.

A consequence of the decline in mortality in Stage Two is an increasingly rapid rise in population growth (a "population explosion") as the gap between deaths and births grows wider. Note that this growth is not due to an increase in fertility (or birth rates) but to a decline in deaths. This change in population occurred in northwestern Europe during the 19th century due to the Industrial Revolution. During the second half of the 20th century less-developed countries entered Stage Two, creating the worldwide population explosion that has demographers concerned today.

Another characteristic of Stage Two of the demographic transition is a change in the age structure of the population. In Stage One, the majority of deaths are concentrated in the first 5–10 years of life. Therefore, more than anything else, the decline in death rates in Stage Two entails the increasing survival of children and a growing population. Hence, the age structure of the population becomes increasingly youthful and more of these children enter the reproductive cycle of their lives while maintaining the high fertility rates of their parents. The bottom of the "age pyramid" widens first, accelerating population growth. The age structure of such a population is illustrated by using an example from the Third World today.